lingering step 2 of the test rename overhaul: make await tests also a directory

frog/tests/await/try_catch_negative_test.dart

Index: frog/tests/await/try_catch_negative_test.dart
diff --git a/frog/tests/await/try_catch_negative_test.dart b/frog/tests/await/try_catch_negative_test.dart
index 179590f161e7abc8d6b5705b9279e83c5402cec4..f9a306672e7ed9d009f559f9286a6d7c11111947 100644
--- a/frog/tests/await/try_catch_negative_test.dart
+++ b/frog/tests/await/try_catch_negative_test.dart
@@ -2,6 +2,9 @@
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
+// Pass VM options to run test through the awaitc compiler:
+// VMOptions=frog/await/awaitc.dart
+
 // Await within a try-catch block, no error occurs.
 
 #import("await_test_helper.dart");